End it with European six-footer (7)
I believe the answer is:
termite
'six-footer' is the definition.
(I've seen this before)
'end it with european' is the wordplay.
'end' becomes 'term' (I've seen this before).
'with' is a charade indicator (letters next to each other).
'european' becomes 'e' (abbreviation e.g. EU).
'term'+'it'+'e'='TERMITE'
(Other definitions for termite that I've seen before include "Ant-like insect which destroys timber" , "Ant-like insect that feeds on wood" , "Six-footer" , "It lives on wood" , "Social insect" .)